DENVER (AP) - Indigo Partners is going ahead with plans to buy Frontier Airlines, even though it failed to reach an agreement with the carrier's flight attendants' union.

The Phoenix-based firm agreed at the end of September to purchase Frontier from parent company Republic Airways Holdings on the condition it could successfully negotiate agreements with the pilots and flight attendants.

Indigo Partners said Friday it reached a tentative labor deal with pilots. In a statement late Wednesday, the firm said that agreement has not been reached with the Association of Flight Attendants, but it will waive that condition.

The deal, which is now based on equity and business conditions, is expected to close later this month pending regulatory approval. Indigo said Thursday the sale price wasn't available but earlier reports said the firm was buying Frontier for $36 million plus assumed debt.

"We are pleased about the progress we have made to resolve major issues and move this acquisition toward closing. We look forward to completing the action and continuing to extend Frontier's reach and service as a leading nationwide, ultra low-cost air carrier," said William Franke, managing partner at Indigo Partners.

Republic Airways chairman Bryan Bedford said in the company's earnings statement on Wednesday that the sale of Frontier will allow its managers to focus on its core business, including low-cost solutions to airline partner brands including American Eagle, Delta Connection, United Express and US Airways Express.

"To all of you at Frontier, I wish you the very best," Bedford said.

Frontier Airlines flight attendants, represented by the Association of Flight Attendants-CWA, said Thursday they want a fair value for the equity and profit-sharing provisions of their contract, regardless of who owns the airline. They said they will work with Indigo Partners to make the airline strong and profitable.